.divstudentdetail {
    width: 100%;
    height: 100%;
    position: absolute;
    background-color: rgba(0, 0, 0, 0.5); //就是这行代码啦
    z-index: 1000;
}

.divcontent {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.divimg {
    margin-top: 20px;
}

img {
    width: 100px;
    height: 100px;
}

.studentdetail {
    width: 600px;
    height: 400px;
    margin: 0 auto;
    background-color: white;
    opacity: 1 !important;

}

.divstudent {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;

}

.spannotice {
    color: red;
}

.goodclass {
    color: green;
}